Construction of cutoff wall is usually underwater concrete,due to the complicated construction technique and quality influenced by many factors, the cutoff wall easy to appear quality problems.The cutoff wall quality testing and evaluation method follows the traditional excavation inspection , drilling and sampling test techniques and injection test,Which is with high destructive effect and costs but low efficiency. Taking a certain water conservancy project as an example, this paper introduces comparative analysis between single transmitter to double receiver and single-emission and single-receiving. Practices show that using ultrasonic testing technique on the one hand can meeting the requirements of engineering quality detection, on the other hand, may also improve working efficiency. The results show that the detecting precision of the two methods are consistent, can popularize use.