Abstract: In order to study the fracture rule of the main roof plate structure under the condition of one side goaf,the mechanical model of the main roof plate structure considering the width and bearing capacity of the coal pillar and the elastic plastic deformation of the solid coal was established.This paper comprehensively calculated and explored the fracture position,sequence and shape of the main roof above the coal pillar area and solid coal area under the condition of one side goaf.The conclusions are as follows.① There are three types of fracture modes of the main roof above the coal pillar area,and with the increase of the thickness h,the elastic modulus E of the main roof and the elastic coal foundation coefficient kt,while with the decrease of the coal pillar width Lm,the coal pillar foundation coefficient ksm,the range of plastic zone Lts,the plasticization degree ξs,and the span L,the change rule of the fracture modes are as follows：“single continuous long arc”→“critical butt joint double long arc”→“separated double short arc”.② The Lm and ksm mainly affected the fracture state of the main roof above the pillar area.With the increase of Lm and ksm,the main bending moment decreased above the solid coal area.③ There are five types of fracture states of main roof above the solid coal area.With the increase of h,E and ξs,while Lts,kt and L decrease，the change rules of main roof plate fracture modes are as follows：“the long edge and short edge fracture line are above the plasticized coal area”→“the long edge fracture line is above the plasticized coal area while the short edge fracture line is above the elastic plastic boundary area”→“the long edge fracture line is above the plasticized coal area while the short edge fracture line is above the elastic coal area”→“the long edge fracture line is above the elastic plastic boundary area of coal while the short edge fracture line is above the elastic coal area”→“the long edge and the short edge fracture line are both above the elastic coal area”.There is a case that the fracture line of the long edge and the short edge are both located above the elasto plastic boundary zone of the coal at the same time.④ The h，E and Lts are larger while L and kt are smaller,the main roof fracture order is as follows:middle part (near the coal pillar side) → long side (three types of location) → short side (three types of location) → coal pillar side (three types of location).⑤ The overall fracture patterns of the main roof can be divided into three types，with the increase of h,E and kt,while the decrease of Lm，ksm，Lts，ξs and L,the change modes of the overall fracture morphology are as follows：closed asymmetric “X” type → critical through asymmetric “X” type → open type asymmetric “X” type.Aiming at the three kinds of mechanical models of main roof plate structure fracture with one side goaf,the important differences among the “trilateral fixed + simply supported model” (the first category),“trilateral elastic foundation + considering the width and supporting capacity of coal pillar model” (single plasticization model,the second category) and the “trilateral elastic plastic foundation + considering the width and supporting capacity of coal pillar” (double plasticization model,the third category) established in this paper are summarized and compared from seven aspects,including model characteristics,fracture influencing factors,initial fracture position,pillar side fracture shape,solid coal side fracture position,overall fracture position and engineering guiding significance.The model in this paper obtains many new conclusions that the traditional models can not get,which effectively makes up for the defects and deficiencies of the traditional models,and has important value in improving the theoretical understanding level and practical guidance of plate fracture in mining engineering.