The invention discloses a cross-platform multi-scene instant messaging method. The method comprises: S1, a client obtains a Socket Server address of a COCO server and establishes a connection; and S2,carrying out instant messaging between the client and the COCO server based on JSON format verification and parameter verification. Instant messaging can be realized without downloading and installing any plug-in, so that the usability and the experience effect of a user are improved. The cross-platform performance of communication is enhanced, and the method can be used in multiple terminals; Scene usage is not limited, message communication is customized, and reusability and expansibility are improved.