The invention discloses a parallel execution automation test system and a method which are based on priority scheduling, the system comprises a test plan module which is used to manage and draw up testing contents, an engineering topology configuring module which is used to topologically allocate test environment and manage the essential information of test environment, a test report and journal generating module for generating test journal and / or test report and a execution control module which is responsible for executing a plurality of test environment, and the invention also comprises an execution control management module, a connection execution control module, an engineering topology configuring module, a test report and journal generating module, a testing use case group with higher priority level which controls the execution control module to preferentially operate in test environment according to testing use case group, when the priority level is same, the relative testing use case group is operated in parallel. The invention greatly improves testing efficiency, which improves recourse utilization ratio, timely avoids ineffective test, and improves availability of test.