The present invention discloses an automatic ticketing system based on task assignment. The system comprises: a task assignment module used for separately putting different ticketing tasks into corresponding message queues according to task types when receiving external requests representing ticketing tasks, wherein the message queues adopt a first-in-first-out data structure; a task take-out module used for taking out the ticketing tasks from the message queues; and a plurality of task processing modules, wherein each task processing module comprises a group of auto-expanding processing threads, each processing thread comprises a processing logic of ticketing tasks, and the task processing modules are used for processing the ticketing tasks by executing the processing threads. The automatic ticketing task system provided by the present invention is a distributed automatic ticketing system with high performance, good availability and good expandability, has the characteristics of ticketing task sequence storage and assignment, high throughput, log transmission, supporting for an abnormality alarm and the like, meanwhile, has good platform independence, and can well support concurrent and asynchronous calling.