Method for correcting NOx model value of original diesel engine in non-standard environment

The invention provides a method for correcting an original engine NOx model value of a diesel engine in a non-standard environment, which comprises the following steps of: establishing a two-dimensional coordinate system taking temperature as a longitudinal axis and environmental pressure as a transverse axis, determining five feature points according to the temperature and the pressure, dividing the whole range into ten regions on the basis of the five feature points, a second quadrant of the coordinate axis comprises an area 1 and an area 2, a third quadrant of the coordinate axis comprises an area 3 and an area 4, a fourth quadrant of the coordinate axis comprises an area 8 and an area 9, a first quadrant of the coordinate axis comprises an area 5, an area 6, an area 7 and an area 10, correction coefficients of the 10 areas are calculated, correction is carried out according to correction value coefficients corresponding to the areas, and the correction value coefficients are obtained. And obtaining an env