Abstract This paper first introduces the characteristics of automatic testing systems and virtual instruments, and then elaborates on the design and implementation scheme of this system from three aspects: system structure, hardware composition, and software design. The computer communicates with the test instruments through the GPIB bus, controls the instruments to send test signals according to the test sequence used by the user, and collects and tests the data of the mobile phone under test, finally displaying the test results. The system scheme is based on universality and scalability considerations, making the system easier to expand and upgrade while achieving automation. Keywords : Virtual instrument; Automatic testing system; Mobile phone testing 1. Introduction With the increasing complexity of high-tech products, automatic testing systems have been widely used in important fields such as aviation, aerospace, weaponry, and energy, becoming a necessary guarantee for the reliable operation of complex systems and equipment. The development level of testing technology also reflects a country's productivity development and modernization level. In order to improve the efficiency of testing and the accuracy of test results, and eliminate the influence of human error, the testing field is promoting the use of automatic testing systems. We use a computer, GPIB bus, and various test instruments as hardware platforms, and utilize the concept of "software as instrument" in virtual instruments. Based on the considerations of universality and portability, we designed this automatic mobile phone testing system. This testing system can be used for various mobile phone testing projects, including static measurement of TX signals, dynamic measurement of TX signals, dynamic range measurement of RX signals, and anti-interference measurement of RX signals. 2. Automatic Test System and Virtual Instrument 2.1 Automatic Test System An automatic test system (ATS) integrates all the necessary excitations and measuring equipment for testing. It is computer-controlled to efficiently complete the acquisition, storage, and analysis of excitation and response signals under various modes, automatically performing status monitoring, performance testing, and fault diagnosis on the Unit Under Test (UUT). The automatic test system is a product of the combination of measuring instruments with computer technology, software technology, interface technology, communication, and network technology. [Full text on the design of a mobile phone automatic test system based on virtual instruments]