A device for calculating an average of nonlinear data includes: an input module for receiving a nonlinear function F and nonlinear data y1and y2; a comparison module for deriving nonlinear data c1 and c2 sorted in a descending order, by comparing the nonlinear data y1 and y2; an index module for deriving an index value d1 according to a preset computation, from the sorted nonlinear data c1 and c2; a lookup table (LUT) memory for pre-storing an LUT of the index value d1 and a variable B by using a preset computation formula, and deriving the variable B corresponding to the index value d1 if the index value d1 is received; and a computation module for receiving c1 of the sorted nonlinear data and the variable B and deriving a final nonlinear output value A through the preset computation.