The embodiment of the invention discloses a traffic flow collection method, device and system based on vehicle-road collaboration. The method comprises the steps of: receiving a data collection mode recommendation request sent by an application terminal; determining an environmental mode; according to the environmental mode and a preset error analysis mode, creating a traffic flow dynamic collection model according to the traffic flow collection mode, calculating error data, and pushing the error data calculated according to the traffic flow dynamic collection model to a database, and calculating, by the database, the traffic flow based on terminal collection data and the error data, and pushing the traffic flow to a display interface of the application terminal. The problem that the relatively large error of road vehicle data collection in natural environments such as light, water fog, and wind and sand and the like affects the accuracy of road traffic flow is reduced.