The invention provides a wave height measurement device and method used for an ice-water mixing environment. The device comprises ultrasonic sensors, laser emitters, a camera and a data processor, wherein the ultrasonic sensors and the laser emitters are fixed on the steel bracket of a ship; the ultrasonic sensors are arranged by being vertical to the water surface and keep a preset safe distancewith the water surface; and the laser emitters and the camera are independently fixedly arranged on the preset position of the steel bracket, wherein the preset position guarantees that reflected laser can be received by the high-definition camera when the laser emitted from the laser emitters are in contact with an ice surface. The system adopts ultrasonic non-contact measurement and overcomes the problem that a traditional measurement method can not measure the ice-water mixing environment. Since the ultrasonic sensors are not in contact with the ice-water mixing environment, the influence of original wave height measurement equipment on an experiment is avoided, the device disclosed by the invention is slightly affected by the environment, the defect that an experiment instrument is likely to wear and tear is overcome, high measurement accuracy is guaranteed, and an experiment device can be easily installed.