Clock synchronization method and device

The invention provides a clock synchronization method and device. The method comprises the following steps that: a first site in a first network acquires transmission time points of n predetermined data transmitted by a second site in a second network, wherein the n predetermined data is transmitted to the first site from the second site along the same transmission path, and n is greater than or equal to 1; and the first site adjusts a first local clock of the first site to be synchronous to a second local clock of the second site according to the transmission time points of the n predetermined data, receiving time points when the n predetermined data is received by the first site, and a time delay, wherein the time delay is a predetermined time delay of time delay test data transmitted from the second site to the first site along the transmission path. Through adoption of the clock synchronization method and device, the problems of high cost, complex networking and low timing accuracy during synchronization of a master network clock and a slave network clock in the prior art are solved, and the effects of lowering the clock synchronization cost, lowering the networking complexity and increasing the positioning accuracy are achieved.