As injector injects coiled tubing into well to a certain depth, the coiled tubing is unable to be injected continuously because of the increasing friction between the coiled tubing and the wellbore. With the core technology being an effective role in the Coanda Effect control switch, the Water Hammer Vibrator may extend the depth of the coiled tubing into the wellbore. Firstly, the paper verifies the effectiveness of the Coanda Effect control switch in Water Hammer Vibrator. Secondly, it optimizes the structure of the Coanda Effect control switch and improves the driving force of the piston of the water hammer vibrator without changing the injection flow rate, pressure and the other boundary conditions. Finally, it obtains varying patterns of the hydraulic cylinder pressure at both ends in the process of the Coanda feedback and trigger action by the experiment of the Coanda Effect control switch to measure pressure at both ends of hydraulic cylinder with the NI data acquisition unit. The results confirm the validity of the optimized Coanda Effect control switch in water hammer vibrator, so as to ensure the implementation and improvement in the water hammer effect of Water Hammer Vibrator.