In the existing literature, for the spatial‐temporal characteristic of ultra‐dense network performances, the joint coverage probability is used to measure the correlation between different links or time‐slots due to channel and topological stability. However, the time‐variation introduces randomness and decreases correlation temporally and spatially due to user mobility, path‐loss and channel fading. In this paper, the expression of the joint coverage probability is derived to simultaneously analyze the effect of correlation and fluctuation among different time‐slots in ultra‐dense mobile networks by stochastic geometry. Specifically, the typical user moves out of the transmission range of the base station with handoff skipping and traditional handoff. In addition, the distance variation caused by the user's movement is considered in the analysis of the temporal correlation and the joint coverage probability. Simulation shows that the temporal correlation coefficient under handoff skipping is gradually greater than that under traditional handoff. The analytical results highlight the differences between the proposed network performance analysis and traditional analysis, validated through simulation.