A large number of studies have shown that the main component of crystallization blockage of tunnel drainage system is calcium carbonate. Crystallization blockage of tunnel drainage pipe will cause poor drainage of the whole drainage system, and in serious cases, cause cracking of tunnel lining, which will bring hidden dangers to the safe operation of the tunnel. In this paper, a device is designed to attach an electric field to the drainage pipe. The electric field is used to affect the movement of molecules in the solution, so as to achieve the purpose of preventing crystallization and pipe plugging. The reliability and practicability of the device are proved through indoor and field tests, which provides a way of thinking for the treatment of crystallization blockage in tunnel drainage system. The results show that the electric field can significantly reduce the amount and rate of crystallization in the tunnel drainage pipe, and can change the shape of calcium carbonate crystal from the tightly bonded hexahedral crystal to the loose and uneven crystal form. After the crystal form changes, the crystal is difficult to adhere to the pipe wall, reducing the probability of crystal blockage; In the indoor test and field test, three electrostatic fields with different voltages of 5V, 12V and 24V are set. The test results show that the best anti crystallization effect can be achieved by using 5V voltage. Compared with the blank group without measures, the anti crystallization effect reaches more than 30%.