Based on a real engineering project, by means of electromagnetic transient simulation software EMTP-RV, a detailed simulation of the Lingtian wind farm in Lingchuan County,Guangxi Province has been modelled, and the electric railway Lingchuan traction station with locomotive load model is connected to the wind farm on the same 110kV bus. Multiple operating conditions such as wind farm with different wind speed and different electric railway load simultaneously connecting to the same substation 110kV bus, are simulated and analysed. A power quality calculation template is developed, and the corresponding power quality indexes are calculated. The simulation results show that the wind farm and electric railway load connected to the same bus will deteriorate the operating conditions of the grid PCC, and cause extremely voltage fluctuation and harmonic injection. Combining with field conditions, a number of improvement advises are put forward from the voltage fluctuation and the power oscillation phenomenon revealed by the simulation, such as: a reasonable scheduling of wind farm active reactive power output, adding harmonic compensation device at electric traction station, set up SVG reactive power compensation automatic control system at 110kV substation. After that, the improved PCC power quality will fulfil the national standards.