Provided are a system and a method for determining an angle. The method includes: determining differences between signal strengths of incident waves received by a first directional antenna of an anchor node from a tested node and signal strengths of incident waves received by a second directional antenna of the anchor node from the tested node at multiple angles, wherein the first directional antenna and the second directional antenna are mounted at a same point, and an area formed by the first directional antenna is partially superposed with an area formed by the second directional antenna; and taking an angle corresponding to a minimum difference in the differences as an angle between a line connecting the anchor node and the tested node and a horizontal reference line. The present technical solution solves the technical problem that a high positioning accuracy and a low complexity of a positioning device cannot be realized at the same time in the related arts and achieves the technical effect of positioning a target accurately when the positioning device is low in complexity.