Abstract: With the advantages of little soil disturbance, good continuity of the test data and good prediction of mechanical properties of in-situ soil, flat dilatometer tests have been used in more and more projects. But the rate of pressurization and other factors bring errors to the test results in flat dilatometer tests, and it’s difficult to evaluate the error and give the emendatory results. The pore water pressure cannot be measured directly by the flat dilatometer tests. Thus, the micro-displacement and pore pressure senors are installed on the flat dilatometer to make it change into the pore pressure and displacement flat dilatometer. It can regulate the results by itself and measure pore pressure directly. The principle, method and procedure of the pore pressure and displacement flat dilatometer tests are introduced. The differences between the pore pressure and displacement flat dilatometer tests and the flat dilatometer tests are also given. The results measured in the pore pressure and displacement flat dilatometer tests are more accurate and stable by comparing with these of the flat dilatometer tests. The in-situ lateral earth pressures in the test field of Weisan Road are measured in the pore pressure and displacement flat dilatometer tests for the first application.