DW1 oil contamination level tester is a kind of portable contamination tester with a voltage blocking membrane. Based on VB6.0, a programming interface and a serial communication program were designed, to real-time collect and display the testing data. The basic VB drawing functions were used to draw curves of flow/volume, realizing the data visualization. Partical number and contamination level of the testing oil could be determined combining with the contamination level model. The software was run. It is shown that the monitoring system has a friendly interface and can be operated easily, it plays a key role to improve the oil contamination model.