Abstract: The wellbore failures caused by complex wellbore trajectory, unreasonable production string combination, production duration exceeding pump inspection cycle and improper downhole operation in unconventional reservoirs generally result in complex fish top. The use of conventional fishing tools presents low efficiency and long well occupation cycle, which seriously affects the normal production of crude oil. Based on the specific analysis of fish falling conditions and the shortcomings of conventional fishing tools in dealing with complex fish tops, four special fishing tools for complex fish tops were innovatively developed, including screw pump rotor falling, eccentric wear broken tubing falling, disc-shaped bending sucker rod and small falling objects. The application effect analysis and evaluation results of Longdong Block in Changqing Oilfield show that the fishing success rates of the four tools are 100.0%, 98.0%, 95.9% and 100.0%, respectively, and the well occupation period is reduced from the average 33.1 d of conventional fishing process to 20.5 d, which effectively improves the crude oil production rate.