To overcome the shortage of traditional test method for tensile property parameters of plant root system, one portable measuring system used in filed work is designed to obtain plant root system tensile property parameters. The system consists of two parts, mechanical device and electronic measuring part. The mechanical device is made up of rack, root holding mechanism and drive system. It adopts the building block design, whose parts can be disassembled quickly. The electronic measuring part is made of sensors, low power consumption MCU data acquisition system, and handheld device developed based on Android platform. It communicates with MCU data acquisition system via Bluetooth, as the terminal of operation, data input and the results display. The experiment results show that the measuring system is portable and accurate. It can get four classical tensile property parameters of root system from the measurement, maximum tensile resistance, tensile strength, modulus of elasticity for tension and ultimate strain. It can also show the stress-strain relationship curve, and inquiry historical data. This system can satisfy the requirements of measuring tensile property parameters of plant root system in the field work. 