Safety system testing is one of the most rigorous and time-consuming requirements in the verification and validation process for reactor protection systems(RPSs).This paper presents the development of a test system for the fully digital and field-programmable gate array-based RPS of the solid fuel(SF) thorium-breeding molten salt pebble bed fluoride salt-cooled reactor(TMSR),denoted as the TMSR-SF1 project,developed by the Chinese Academy of Sciences.The test system is applied to the RPS to ensure that it fully meets its designed functions and system specifications.We first introduce the testing principles and methods.Then,the hardware component designs and the software program development of the test system are discussed.Finally,the test process and test results are discussed and summarized. Safety system testing is one of the most rigorous and time-consuming requirements in the verification and validation process for reactor protection systems (RPSs). This paper presents the development of a test system for the fully digital and field-programmable gate array-based RPS of the solid fuel (SF) thorium-breeding molten salt pebble bed fluoride salt-cooled reactor (TMSR), denoted as the TMSR-SF1 project, developed by the Chinese Academy of Sciences. The test system is applied to the RPS to ensure that it fully meets its designed functions and system specifications. We first introduce the testing principles and methods. Chen, the hardware component designs and the software program development of the test system are discussed. Finaally, the test process and test results are discussed and summarized.