Abstract: The Non-Inductor Capacitive Pulsed Power Supply (NICPPS) is one effective way to achieve the miniaturization and lightweight of the pulsed power supply, thus greatly facilitating the engineering progress of the electromagnetic launch technology. During the operation process of the NICPPS, the turn-on delay jitter of the thyristor is an important factor which can affect the reliability of the NICPPS, and its influences need to be taken into serious consideration. In this paper, based on the sub-circuit model of the high-power thyristor and the dynamic load, the performances of system outputs and semiconductor switches are both compared and analyzed, and the simulation is verified by the experiment. The jitter threshold of the first conducted module is discussed, which can be used as a frame of reference for the further development of the NICPPS. The result shows that the system's efficiency rises by 2.13 % without pulse forming inductors, and the output performances are insignificantly affected by the turn-on delay jitter. The higher efficiency makes further improvements on the miniaturization and lightweight of the NICPPS on the condition of the equal muzzle velocity. The system's volume and weight decrease by 23.1 % and 18.9 %, respectively. However, the turn-on delay jitter has a negative impact on operation safety of the thyristor in the first conducted module. Attention must be paid to the high rate of current rise, which could cause the current spike. When the jitter threshold of the first conducted module is not greater than 0.1μs, the increase in the number of conducted modules can reduce the rate of current rise in the first conducted module effectively. Taking the limit value of the rate of current rise as boundary condition, the number of conducted modules rises in the form of power function with the linear increase of the turn-on delay. According to the analysis of the system performances, the NICPPS is feasible for the augmented railgun system in terms of engineering application.