The invention provides an application accessing method for an open platform. The application accessing method comprises the following steps: S10 receiving an application request sent by an application side via the open platform, wherein appkey information, an appsecret, a sessionkey and request parameters are included in the application request; S20, carrying out authorization verification on a user according to the received application request, and sending an application verification request to the application side according to an authorization verification result; S30 receiving the appsecret returned by the application side after finishing the verification, and carrying out verification on the appsecret; S40 further verifying the sessionkey according to an appsecret verification result; and S50 executing the application request according to a sessionkey verification result and the request parameters, and feeding a response result back to the application side. The dual protection is carried out on an application accessing process from a communication security level and a user security level, thereby improving the security performance of the user in the application accessing process.