The invention provides data sending and receiving methods based on LoRa. The sending method comprises the steps of performing CRC coding on original data to acquire a first sequence, wherein the length of the first sequence is a first parameter; if a current channel is polarized to a second parameter of sub-channels, selecting the first parameter of sub-channels with the maximum channel capacity from each sub-channel to serve as information bit transmission channels and recording numbers, wherein the second parameter is a polarization length; based on each number, placing each piece of bit information in the first sequence to a corresponding bit of the second sequence to form a third sequence, wherein the length of the second sequence is the second parameter, and each piece of bit information is 0; performing linear conversion on the third sequence to acquire a fourth sequence; deleting the corresponding bit in the fourth sequence according to the serial number of the bit to be deletedto form a fifth sequence; and modulating and then transmitting the fifth sequence via a LoRa module. According to the method provided by the invention, the anti-interference capacity of LoRa channeltransmission is enhanced, and the transmission reliability of the LoRa Internet of Things is improved.