Abstract: A quick and easy multi-colour flow field survey technique has been developed that makes it possible to acquire and present S-colour and 15-detail graphical records of total pressure. This technique should be considered as an utilization and modification of Crowder's technique with light emitting diodes （LED） （ 1 ）.However, the varieties of colour from LEDs are not enough to display total pressure isobar pattern of flow field in more detail. Obviously, the increase of varieties of colour improves spatial resolution of flow field mapping. For this purpose, a multi-colour emitting system with feeding accessory has been made, which enable to yield multi-colour photos of vortex flow field by close scanning of a fast-response total pressure probe.Therefore, a large quantity of useful information can be extracted from them. Its features and potential applications are discussed. Some experimental results are also presented.