The invention discloses a low-PAPR sequence designing method for a wireless communication system. The low-PAPR sequence designing method comprises the steps of firstly setting relevant parameters of designed sequences, then performing multiple-time iteration, generating length-designated sequences with multiple elements 0 and 1and meeting Bernoulli distribution of designated probability density parameters according to the parameters during primary iteration, screening the sequences according to PAPR of the sequences, updating parameters for next-time iteration based on the screened sequences, and finally performing mapping on the sequences with lowest PAPR to obtain low-PAPR sequences with elements -1 and 1 after stopping iteration. Compared with the prior art, the low-PAPR sequences with any length can be designed, include +1 and -1 elements and have good self-related performance. By means of the method, the low-PAPR sequences can be still obtained under the condition that specific values are set for specific positions of the sequences, and application scenarios and an application range of the low-PAPR sequence designing method are further widened. The low-PAPR sequence designing method can be applied to but not limited to design of long-training sequences of OFDM systems.