Abstract: The present invention discloses a microwave heating system for desorbing contaminated soil, comprising: a feeding module; a heating cavity; a first microwave suppression cavity; a second microwave suppression cavity; a conveyor belt; a feeding device; and an exhaust module. The feeding device is arranged above the first microwave suppression cavity or the second microwave suppression cavity, and the feeding device contains a microwave absorber material. The invention further discloses a microwave heating process for desorption of polluted soil. With the microwave heating system and process for desorbing contaminated soil, the contaminated soil can be heated quickly and uniformly, and quickly cooled and taken out smoothly.