In order to solve the problem of well fluid ejection polluting the environment during the operation of pumping unit monitoring well, and meet the needs of non moving string passing through annulus test during production, the wellbore blowout prevention technology with annulus testing is developed. The process string is mainly composed of Y445 packer, valve core downhole blowout prevention switch and poke rod. During pump inspection operation, the valve core downhole switch is closed to realize blowout prevention, and it is opened during production with the minimum internal diameter Φ36 mm, providing a central channel for the lifting and lowering of the test instrument. Through finite element analysis, the sealing and anchoring performance of process string under different casing pressures of 0 ~ 25 MPa is simulated. The maximum blowout prevention pressure is 28.4 MPa and the jacking force is not less than 422 kN. The indoor test results show that the process string is safe and reliable under 25 MPa casing pressure. This technology has been tested in 5 wells in a Oilfield, and the through annulus testing instrument for production profile passes smoothly and has no jamming. Two wells are operated for secondary pump inspection, and there is no overflow out of well during the whole construction process. This technology realizes pump inspection operation without well killing and through annulus test without pulling string.