The invention discloses a spliced model online putting method based on application host and slave online check of a dispatching automation system. The method comprises the steps of establishing an offline system of the dispatching automation system; synchronizing the offline system and an operating system; splicing models in the offline system; issuing a spliced model to an application slave; checking and verifying the spliced model by employing the application host and the application slave in sequence; confirming the spliced model in the dispatching automation operating system if the verification is successful; carrying out model backspace operation if the verification is unsuccessful, thereby recovering the model synchronized to the application host to an old model. According to the method, double-verification is carried out on the spliced model through the application host and slave of the dispatching automation operating system, through adoption of means such as backspace of the spliced model, the spliced model is effectively verified before the spliced model is put online, and the security problem of the spliced model after the spliced model is put online can be solved.