Space-based information support is crucial in natural disaster rescue and hotspot-region monitoring. Typical space-based information support includes in-orbit satellite maneuvers and emergency space launches, which regard mission response time as a critical performance metric. Therefore, it is essential to model the space-based information support process and identify potential bottlenecks. This study employs a stochastic Petri net to model the space-based information support process and evaluates system efficiency. Comprehensive performance analysis including the busy probability of places, utilization of transitions, and system delay is conducted on specific case. Experimental results quantitatively evaluate the efficiency of each procedure and identify the bottlenecks in the workflow. Optimization experiment and corresponding recommendations on these bottlenecks are provided to enhance space-based information support capabilities in emergency scenarios.