The invention discloses a visitor password generation method, a verification method, a server and an intelligent door lock. The generation method comprises the following steps: acquiring starting time, ending time, a using frequency and an equipment identifier; performing first coding operation on the starting time, the ending time and the using frequency to obtain a first code; carrying out signature operation on the first code and the equipment identifier to obtain a first signature value; and carrying out second coding operation on the first signature value and the first code to obtain a second code, and taking the second code as a visitor password. According to the technical scheme, a series of coding operations can be carried out according to the starting time, the ending time, the using frequency and the equipment identifier to generate the unique visitor password with the timeliness.