The invention discloses a multifunctional washing trolley and a washing control method. The multifunctional washing trolley comprises a trolley body, a water inlet pump, an ultrasonic probe and an electric control layer; the trolley body is provided with a water inlet, a water return opening, a liquid supplementing opening and a liquid discharge opening; the water inlet pump is communicated with the water inlet; the ultrasonic probe is fixedly arranged on the inner side wall of the trolley body; and the electric control layer is fixedly arranged in the side wall of the trolley body, and the electric control layer is electrically connected with the water inlet pump and the ultrasonic probe. By means of the multifunctional washing trolley and the washing control method, a temperature control unit, a timed control unit and a liquid level control unit are arranged for achieving accurate control over all functions of the multifunctional washing trolley, and the complex environment and requirement of an engine testing room are met; and meanwhile, the ultrasonic probe is arranged, automatic washing of the trolley is achieved, and the cleanliness of the multifunctional washing trolley is guaranteed while the cleanliness of the testing equipment is guaranteed.