The invention discloses a method, a system and terminal equipment for mobile payment. According to the method, the system and the terminal equipment, the transaction is safe by controlling the payer distance and sound wave frequency, the possibility that transaction data is intercepted, stolen and tampered is reduced, the transaction efficiency is high, and the transaction data is transmitted in a form of sound waves. Especially, the sound waves are transmitted by using loudspeakers and microphones on terminal equipment, hardware equipment is not required to be modified or increased, the expansibility is high, transplantation is easy to perform, low end mobile phones are compatible, the cost is low, the transaction is safe by controlling the distance and the frequency, the possibility that the transaction data is intercepted, stolen and tampered is reduced, the transaction efficiency is high.