Abstract: This invention discloses an information coding and transmission method that is based on UDP network transmission protocol. It consists of the following procedures: (1) define data transmitting terminal A; (2) define data transmitting terminal B; (3) data transmitting terminals A and B are pre-agreed; (4) establish mapping relationship between data transmitting terminals A and B; complete data transmission and communication according to characteristic value m. The beneficial effect of this invention lies in that implicit data transmission enables the actually transmitted data to be independent from the method of network information encryption; mapping relationship between data transmitted and actual data is pre-set by the data transmitting terminals A and B, so as to achieve strong confidentiality and enable equipment in the encrypted wireless network to send information to those outside of the network by connectionless means.