The bidirectional hydraulic jar is designed to form a heavy duty coiled tubing string in conjunction with the accelerator. The jar delay device allows the stretched energy to be stored in the accelerator and the extended string. When the energy is released, it will produce a large impact force, resulting in a jarring effect, which will loosen the stuck tool. The bidirectional hydraulic jar is filled with fluid with a certain viscosity. Under the action of pull/thrust, the fluid passes through the measuring mechanism with strict control of the clearance. When the viscous fluid passes through the fine gap, there will be a delay effect, and the fluid pressure increases while energy is stored. The viscosity of the jar fluid determines the energy storage time delay, and the fluid with high viscosity will produce a longer delay time. By testing and adjusting the fluid viscosity, the jar delay time and the jar force can meet the requirements of use.