The invention provides a mobile detection system for power grid adaptability testing for a high-altitude photovoltaic power station. The mobile detection system comprises a step-down transformer container connected with a power grid, a boosting transformer container connected with a tested generating unit of a photovoltaic power station, and a centralized control container. The step-down transformer container consists of a network side switch cabinet and a step-down transformer connected to the centralized control container. The boosting transformer container includes a machine-side switch cabinet and a boosting transformer connected to the centralized control container. The centralized control container includes a grid disturbance device and a centralized control operation device; the grid disturbance device is used for simulating the operating state of the power grid; and the centralized control operation device is used for adjusting the working state of the mobile detection system and putting forward technical requirements that need to be met by the system in a high-altitude environment. Compared with the prior art, the provided mobile detection system has the following beneficial effects: power grid adaptability testing optimization is realized; the detection process becomes reliable; and the high altitude requirement can be met.