Through analyzing the advantages and disadvantages of soil penet ration experiment device, a testing device is developed, which can be applied in testing soil penetration and runoff of slopeland. The device can simulate a bread rainfall intensity chart(0.4～10mm/min),which simulation precision is higher and duplication is well, the error no more than 5.5 percent. The test result shows that the device is a good tool for researching soil penetration, runoff and sediment of slopeland.