The heat dissipation of air cooling gradually reaches limitation, to the point where it unable to meet the cooling requirement of high-power chips in AI (Artificial Intelligence) server. Two phase immersion liquid cooling technology has become a focus of research on servers due to the excellent performance on heat dissipation ability and heat dissipation efficiency. Multiple chips are usually contained in high-performance AI servers. The boiling that occurs on the surface of high-power chips affects each other in immersion cooling condition, especially for cascaded chips in vertical. This paper presents a cascade-chips model to study the heat and mass transfer processes during two-phase immersion cooling using HFE-7100. The Non-Equilibrium boiling model was used to simulate the heat transfer during boiling. Three parameters involved in boiling model e g. bubble departure frequency, bubble departure diameter and nucleate site density, were analyzed, and the empirical models describing these parameters were modified according to the condition of cascaded chips in vertical. Simulation results shows that the chip temperatures of modified model are highly consistent with the experiment. The temperature of the upper chips is lower than the lower chip due to the flow disturbance. While the nucleate site density over the upper heatsink is lower than the lower chip, the higher bubble departure frequency taking away more heat.