The delayed breakdown characteristic is crucial for achieving rapid conduction in PIN diodes. This paper addresses the challenges associated with analyzing the physical process involved in delayed breakdown conduction, primarily due to its short duration. An integrated diode model based on the PIN structure has been designed and validated in our study. Firstly, a numerical simulation model of the diode was developed using TCAD. The simulation results indicate that, influenced by a rapid rising high-voltage trigger pulse with a rise time of 520 V/ns and a magnitude of 1000 V, the breakdown voltage of the diode could reach 1.76 times its static reverse breakdown voltage. The accuracy of the established model was further verified by examining changes in the carrier concentration and the evolution of the internal electric field during the conduction process. Secondly, based on bipolar carrier diffusion theory and the parameters obtained from TCAD simulations, the base region parameters of the diode were processed using the Laplace transform and Pade approximation method for equivalent circuit representation. Finally, utilizing the equivalent circuit parameters of the base region and considering conductance modulation effects, an integrated model of the PIN diode was constructed based on its delayed breakdown characteristics. This model was simulated and verified in PSpice software, demonstrating that under the same triggering pulse, the conduction process of the diode device is basically consistent with the TCAD simulation results. This study provides a straightforward and effective circuit analytic method for exploring the reverse delayed breakdown characteristics in rapidly conducting diodes.