The invention relates to the technical field of cloud host network utilization, and in particular to a method for performing cross-network service access based on a cloud host. The method for performing cross-network service access based on the cloud host disclosed by the invention comprises the following steps: 1, a cloud host with a fixed external network IP address is obtained; 2, a VPN and a network service access agent tool are set up on the cloud host; 3, the VPN user is configured to have a fixed dialup IP address, and a mapping relationship of the network service access agent is configured; 4, the VPN is dialed up on the host providing the cross-network service of the intranet, a fixed IP is directly distributed, and a fixed association is established with the cloud host; and 5, the external network accesses the intranet service through the cloud host, and jumps to the intranet service by the agent tool, thereby implementing the cross-network service access of the external network through the cloud host. The invention solves the problem that the intranet cannot provide the fixed external network service, and utilizes the low price characteristic of the service host to reduce the cost of obtaining the public network IP, which provides an efficient and feasible method for small-scale external network access services.