Landfill gas (LFG) extraction tests were carried out at a wet landfill of municipal solid waste (MSW) in Southern China. The influences from leachate level, well number and vacuum pressures on the LFG extraction rate were investigated. The efficiency of LFG collection and recovery at this kind of landfill was evaluated. It was found that the LFG collection efficiency was less than 30% when the average buried depth of leachate level was about 3 m in the landfill. The influence radius of extraction wells ranged from 8.85~30.53 m under different vacuum pressures and leachate levels. The average LFG generation potential of MSW at this landfill was 143.69L/kg, and the average LFG generation rate of MSW was 0.173a^-1. In addition, field investigation indicated that the compressed air pressure for leachate pumping and the permeability around the vertical well were the main influence factors on the leachate drainage performance of pumping wells. On the base of the LFG extraction tests and the field investigation, practical measures were proposed to enhance the LFG collection rate at landfills with a high leachate level. The LFG collection rate at this landfill was increased from 2240m³/h to 5900m³/h after extra 66 pumping wells were put into use to drawdown the leachate level.