1. A system for motion evaluation, comprising: a plurality of sensor apparatuses photographing a user to acquire user's joint data; an analysis apparatus performing calibration and synchronization on the joint data input from the plurality of sensor apparatuses to generate a user's skeleton and using pose vectors calculated for each body part to compare a user's pose with an expert's pose; and a display apparatus outputting a user character moved depending on a user's motion by using the skeleton, together with an expert character and outputting the comparison result, wherein the analysis apparatus includes: a calibrator setting a coordinate of one of the plurality of sensor apparatuses as a reference coordinate and calculating a coordinate transformation matrix for transforming coordinates of the rest sensor apparatuses into the reference coordinate; a synchronizer recording time for the plurality of sensor apparatuses to start to capture and interpolating the joint data based on the fastest capture time to synchronize the joint data of the plurality of sensor apparatuses; a mixer generating candidate segments depending on the number of joints tracked by the plurality of sensor apparatuses and included in a segment, selecting a segment having a highest tracking weight value from the candidate segments, and mixing the joint data of the selected segment to generate the skeleton for the user's motion; a comparator defining the pose vectors calculated for each body part and using the pose vectors to compare the user's pose and the expert's pose having different body proportions with each other; and a result calculator storing the calibrated and synchronized joint data, outputting the user character, to which the skeleton is applied, through the display apparatus, and generating the comparison results using the pose vectors and displaying the generated comparison results through the display apparatus.