There are several problems in the ultra-low temperature refrigeration control system on the tuna fishing boat, including the low degree of automation, unsatisfactory monitoring effect and poor monitoring conditions. In order to solve these problems, a tuna fishing boat ultra-low temperature cold storage refrigeration monitoring system was designed and developed by using the virtual instrument technology, based on LabVIEW. This system achieved a real-time monitoring, and displayed a unit’s data and dynamic curves. Moreover, it also included a data processing and storage, a control parameter settings, an electronic expansion valve real-time status monitoring, a valve control and an output display. The experimental results indicated that this system could be operated stably and automatically, and used to get detection timely and accurately, with a friendly human-machine interface.