The invention provides a positioning method, a system, a device and a storage medium for an unmanned vehicle, wherein the method comprises the following steps: setting a plurality of positioning markpatterns on a lane line, and establishing a mapping relationship table between each positioning mark pattern and spatial coordinates; capturing a picture of the road surface in front of the vehicle, and detecting whether the picture has a mark line with a preset mark pattern, if not, adopting a global positioning mode for controlling; if so, obtaining a accuracy of local positioning and a accuracyof global positioning in a current state; determining whether the accuracy of the local positioning in the current state is higher than the accuracy of the global positioning, and if so, adopting a local positioning mode for controlling; If not, adopting the global positioning mode for controlling. According to the positioning method, the system, the device and the storage medium for the unmannedvehicle, the most suitable positioning mode can be automatically selected in different states, and the safety and accuracy of the unmanned vehicle are improved.