Abstract: According to the requirement of high torsional density of spindle and hub in wind turbine, the author proposes the torsional structure of large plane friction pair and gives the torsional formula of plane friction pair, analyzes the factors affecting the torsional capacity of friction pair and the measures to improve the torsional capacity of plane friction pair, and further proposes the uniform cross-combination connection mode of hydraulic tightening bolt and high-strength bolt. Without changing the size of the connector, this method improves the torsional ability to a certain extent, and is convenient to install and disassemble, strong stability, good reliability, long service life, and is worth popularizing and applying.