With the rapid development of V2X (Vehicle to Everything), high-accuracy positioning technology has drawn the attention of operators and manufactures. In consideration of automation levels, operated condition or other factors, different V2X application scenarios are required different position accuracy. In general, the quality of positioning has a significant impact on the accuracy of service triggering. The vehicle can adopt different positioning technologies according to its own application scenarios' requirements. As the essential component of C-V2X equipment, GNSS (Global Navigation Satellite System) and RTK (Real-time Kinematic) are most basic positioning technology. However, this technology is not suitable for whole conditions, such as dense urban areas, tunnels or underground parking. The location service providers always provide the highest value of position accuracy in open environment, but positioning quality of the special environments is unknown. Therefore, this paper proposes a test method to evaluate the performance of GNSS and RTK in actual environments. This method can evaluate multiple vehicle terminals' positioning quality from different location service providers simultaneously. Finally, according to the actual test results, this paper estimates whether key performance indicators of GNSS and RTK can meet the application requirements and analyses the influence of positioning for V2X applications scenarios.