The present disclosure provides an experimental device for simulating the erosion of a tubing string caused by sand production. The experimental device includes an autoclave, a circulating assembly, a power assembly, a monitoring assembly, or a three-phase feeding assembly. The circulating assembly is sealed and arranged in the autoclave, the circulating assembly includes a circulation loop formed by straight pipes and elbows. The power assembly includes a pump arranged on the circulation loop. The monitoring assembly includes a flowmeter and a temperature and pressure sensor for detecting the circulation loop, and the temperature and pressure sensor is communicatively connected with a PC. The three-phase feeding assembly includes a feeding pipe that is in fluid communication with the circulation loop, and the feeding pipe is connected with one or more gas tanks, a sander feeder, and one or more liquid tanks, respectively.