Abstarct: Liner, single-reflection and multi-reflection time-of-flight mass spectrometers have been simulated and studied using CST simulation software. Then, the ion-beam focal point of the reflection time-of-flight mass spectrometry are obtained, and then the optimal ion-beam focal point in the reflection time-of-flight mass spectrometry are determined. with the help of CST software, the time-of-flight ions has been recorded in liner, single reflection and multi-reflection time-of-flight mass spectrometers. Then time-of -flight two different ions emitted from the ion source are obtained in Liner, single-reflection and multi-reflection time-of-flight mass spectrometers and they are compared with each other. The histogram plots the number of ions reached by the detector in terms of time-of-flight, which is distributed as a Gaussian distribution, and from the graph, the temporal and mass resolving power of the liner, single-reflection and multi-reflection time-of-flight mass spectrometers are obtained and compared.