An embodiment of the invention discloses a user side commercial electric quantity settlement calculation method based on deviation examination and a device thereof. According to the method and the device, in consideration of a fact that an electric power market reflects an economic benefit, an established computing model does not restrain user power consumption amount increase to a certain extent. Based on an actual power consumption level of a user, two factors of no examination and one-time deviation settlement examination on the condition of positive deviation of an actual power consumption amount are considered; an objective and proper settlement solution can be generated. According to related rules and orders in national electric power market reforming, accurate predication for month power consumption amount by the user is encouraged. On the condition of higher electric power amount prediction accuracy, benefit maximization is realized. Load predication consciousness and planned power consumption consciousness are improved to a certain extent. Furthermore an on-hand stock market is cultivated.