The traditional centralized metering method for oil development is difficult to get the parameters linked to the oil-gas-water three-phase flow in a single oil well. To address this issue, the volume of fluid and finite element analysis are used in this study to optimize the structural parameters and impacts of the gas-liquid separation on the basis of the numerical simulation model of the measuring device. Therefore, the optimal structural parameters of the monitoring device are determined. Based on the afore-mentioned research, a permanent multi-well group single-well patrol three-phase flow multi-parameter measuring device is developed for long-term, stable and reliable utilization in the existing centralized metering environment. In addition, the experimental studies are conducted on a permanent multi-well group single-well patrol three-phase flow multi-parameter measuring platform built for oil production. The experimental results show that the developed device has less than 10% error in water holdup and gas holdup measurement and less than 4% error in flow rate measurement under mixed fluids such as gas and liquid phase flow rate range (5~ 70 m 3 / d) and liquid phase water holdup range ( 50% ~ 90% ). Both simulations and experiments demonstrate that measuring device performs well in water holdup measurement.