In order to study the characteristics of abnormal fluid pressure in eastern Kuqa depression and its influence on tectonic deformation, we calculated the fluid pressure in mudstone interval of 25 wells in study area by using “equivalent depth method”, based on the drilling data, logging data and well completion data. Correcting the calculated fluid pressure according to the measured fluid pressure and depicting the characteristics of abnormal fluid pressure of different tectonic belts in study area, by which, we fitted the relationship between fluid pressure and depth and estimated the effective coefficient of friction of the basal fault µb* is 0.138∽0.238. Calculated the strength of basal fault F （should be equal to µb*） is 0.103 4∽0.172 9 by using “critical-taper wedge mechanics”, based on the seismic section A-A’, B-B’. There is a good agreement between effective coefficient of friction of basal fault µb* and basal fault strength F, which indicated that calculated effective friction coefficient of the basal fault is dependable. If there is no fluid overpressure in study area, the effective coefficient of friction of the basal fault should is 0.342∽0.485, explained that it is the widely developed fluid overpressure in the study area that effectively reduced the effective friction coefficient of the basal fault 59.1%∽69.8%, which means the required shear stress to make shear failure occurred reduce by a large margin in Yiqikelike belt and Qiulitage tectonic belt.