Objective   To improve the high-sensitivity mechanical test device for detecting the properties of small tension membranaceous biomaterials produced in our laboratory and Chongqing University and examine its accuracy and stability.    Methods   The original airliquid pressure loading system was replaced by an airy pressure loading system. The clamp was upgraded to a visual clamping system which can be moved along the axial direction and clamped firmly and accurately. The original pressure sensor was replaced by a higher precision sensor with a measurement range from 0 to 20 kPa. The parameters in the software were adjusted accordingly. The accuracy and stability of the device were tested.    Results   The original device was improved as a small

delicate and easy to operate device with reliable clamps and visible change in its test parts. Accuracy testing showed that the reference error was very small

ranging from -0.30% to +0.29%. Stability testing showed the data obtained from the 5 groups tested at different time were (18 723±16)

（18 705±5）

(18 720±23)

(18 731±15)

(18 733±20) Pa

and there was no significant difference（P0.05）.    Conclusion   The improved device is suitable for detecting the tension strength of small tension membranaceous biomaterials such as tissue engineered skin.