Abstract: Coalbed methane is an important unconventional resource and its productivity evaluation is very significant for the efficient development of coalbed methane. Based on the data of formation pressure, permeability, initial gas content and Langmuir pressure, etc. in Qiyuan Coal Mine of Shouyang block, the software COMET3 is used to evaluate the production capacity of CBM fractured horizontal wells, and the factors influencing well productivity such as horizontal section length, horizontal well spacing and fracture parameters are studied in this paper. The results show that the horizontal section length, horizontal well spacing, fracture amount, fracture half-length and fracture conductivity can significantly affect the productivity of horizontal well. When the horizontal section length is less than 600 m, the variation of gas production of CBM well is sensitive; the heterogeneity of coal bed is very important for the high yield of CBM well; the fracture amount is the main factor controlling cumulative gas production, followed by fracture conductivity and fracture half-length; with the decrease of horizontal well spacing, the cumulative gas production will increase, but too small well spacing does not work well