Abstract: With the rapid development of semiconductor components, multiple independent subsystems such as traditional civil aviation radars, meteorological radars, satellite navigation systems, and vehicle-mounted radios have been evolved into integrated microsystems where multiple functions work in coordination. The design of the front-end radio frequency module has been evolved from traditional hybrid integration technology and multi-chip channelization technology to radio frequency system-in-package (RF-SIP) multi-chip modular technology. As a result, the volume of the system can be reduced to half of its original size. The RF-SIP using three-dimensional stacking technology can be integrated with single, double, or even multiple frequency conversions internally. However, within its limited volume, the mixer spurious suppression is a challenging problem. In order to better avoid the generation of spurious signals, many previous studies have been drawn on in this paper, and the testing experience in practical work has been combined to study a new method for calculating mixer spurious. The completeness problem of calculating mixer spurious in traditional calculation tools has been solved by this method. It has been programmed into a small tool using C#, integrated into a microwave auxiliary testing software Locverk PBS. For engineers engaged in radio frequency component design and testing, as well as solution planners, it can be used to assist in the analysis and design of the mixing scheme at the initial stage of a project, and the design and research and development cycle can be reduced.