Urine test instrument is an important medical diagnostic equipment, however the traditional instrument urine has been designed with great limitations. In order to aviod the disadvantage of large volume and high cost, this paper designed a portable wireless urine test instrument based on the principle of the capacitive sensor. This system take capacitive sensor TouchSenser as the detecting element and using Pcap01 ACAM to detect the capacitance change of every unit. The controller of this system was STM32L152, an 32bit microcontroller of STMicroelectronics, with low power consumption. Low power Bluetooth chip Da14580 of Dialog Semiconductor was used to wireless communicate. In order to obtain accurate capacitance value, proposes a data processing algorithm based on Pauta criterion. The experimental results show that the urine test instrument has the characteristics like high precision, flexibility and so on.