The invention provides a method and a device for elliptic curve cryptography point multiplication operation. The method comprises the steps that a controller selects a data flow to be process and stores the data flow to a first memorizer; a point multiplication operational unit sequentially reads out data bits in the first memorizer, and performs first operation on the data bit when the data bit is 1 and stores the result of the first operation to a second memorizer; the point multiplication operational unit performs second operation on the data bit when the value of the data bit is 0 and stores the result of the second operation to the second memorizer. By adopting the method and the device, the power dissipation for realizing elliptic curve cryptography point multiplication operation can be effectively reduced.