The invention relates to a rainwater recycling and reusing system of a construction site. The rainwater recycling and reusing system comprises a rainwater recycling system, a treatment system, a rainwater reusing system and a recharge system. The rainwater recycling system comprises a rainwater well, a roof rainwater collection box and a ground rainwater drainage ditch, wherein the roof rainwater collection box and the ground rainwater drainage ditch are communicated with the rainwater well. The treatment system comprises a settling tank communicated with the rainwater well, and the settling tank is a three-level settling tank which comprises a first-level settling tank body, a second-level settling tank body and a clean water tank body. The rainwater reusing system comprises a car washing system circularly communicated with the first-level settling tank body and the clean water tank body, and a rainwater collection tank circularly communicated with the clean water tank body. The recharge system comprises a municipal tap water pipe network and a municipal drainage pipe network which are communicated with the rainwater collection tank. By means of the rainwater recycling and reusing system, the problems that rainwater in the construction site cannot be fully utilized, accordingly water resources are wasted, and the construction cost is increased are solved.