To minimize dynamic measurement error in an underwater laser scanning system, a shake reduction method is proposed. Feature points are used to construct a dynamic coordinate, estimate the position and attitude of the scanning system synchronously, and correct the scanning results, so as to achieve high-precision measurement under severe shaking conditions. Experimental results show that the dynamic measurement error is <2  mm and the RMS is <2  mm when the target is located 3 m away, which verifies the feasibility of the method.