An information transmission method for an ultrasonic transmitter, comprising: encoding information to be transmitted to obtain an ultrasonic encoded signal, wherein the information to be transmitted comprises a plurality of characters arranged in sequence, and encoding the information to be transmitted to obtain the ultrasonic encoded signal comprises: sequentially converting the plurality of characters into a plurality of frequency values based on a correspondence between characters and frequency values; obtaining a plurality of encoded sub-signals corresponding to the plurality of characters based on the plurality of frequency values; and sequentially encoding the plurality of encoded sub-signals corresponding to the plurality of characters to form the ultrasonic encoded signal; obtaining an ultrasonic transmission signal based on the ultrasonic encoded signal and an ultrasonic wake-up signal, the ultrasonic wake-up signal for waking up an ultrasonic receiver to decode the ultrasonic encoded signal; and transmitting the ultrasonic transmission signal to the ultrasonic receiver; and characterised in that: sequentially encoding the plurality of encoded sub-signals corresponding to the plurality of characters to form the ultrasonic encoded signal comprises: when frequencies of adjacent encoded sub-signals are the same, directly connecting the adjacent encoded sub-signals; and when frequencies of adjacent encoded sub-signals are different, connecting the adjacent encoded sub-signals through frequency shifting. encoding information to be transmitted to obtain an ultrasonic encoded signal, wherein the information to be transmitted comprises a plurality of characters arranged in sequence, and encoding the information to be transmitted to obtain the ultrasonic encoded signal comprises: sequentially converting the plurality of characters into a plurality of frequency values based on a correspondence between characters and frequency values; obtaining a plurality of encoded sub-signals corresponding to the plurality of characters based on the plurality of frequency values; and sequentially encoding the plurality of encoded sub-signals corresponding to the plurality of characters to form the ultrasonic encoded signal; obtaining an ultrasonic transmission signal based on the ultrasonic encoded signal and an ultrasonic wake-up signal, the ultrasonic wake-up signal for waking up an ultrasonic receiver to decode the ultrasonic encoded signal; and transmitting the ultrasonic transmission signal to the ultrasonic receiver; and characterised in that: sequentially encoding the plurality of encoded sub-signals corresponding to the plurality of characters to form the ultrasonic encoded signal comprises: when frequencies of adjacent encoded sub-signals are the same, directly connecting the adjacent encoded sub-signals; and when frequencies of adjacent encoded sub-signals are different, connecting the adjacent encoded sub-signals through frequency shifting. when frequencies of adjacent encoded sub-signals are the same, directly connecting the adjacent encoded sub-signals; and when frequencies of adjacent encoded sub-signals are different, connecting the adjacent encoded sub-signals through frequency shifting.