Abstract: Aiming at the problem that the untrusted server in spatial crowdsourcing obtains the user's real location information, resulting in the disclosure of user privacy, we propose a location privacy protection method of space crowdsourcing based on hierarchically well-separated tree (HST), which can protect the user's location privacy and guarantee the effectiveness of the task assignment. It constructed the set of position points into an HST and designed a differential privacy protection mechanism based on HST to conduct disturbance processing on the user's location node. The theory shows that the mechanism meets the Geo-indistinguishability. Experimental results show that under the same privacy budget, the proposed method is significantly better than the existing differential privacy mechanism in the total distance of task assignment.