With wide adaptability, gray system theory is a science theory of studying poor information. Multivariable gray MGM (1, n) model parameter can reflect the interaction and mutual restraint between a number of variables. For the response time and reducing formula of non-equidistance MGM (1, 1), objective function is the minimum average relative error between reduction sequence and original sequence of MGM (1,1) model. The first component of multivariate non-equidistance gray model MGM (1,n) data decompression is regarded as an initial value of gray differential equation, and the matrix A and B of model MGM (1, n) as design variables. Thus, a non-equidistant optimization model MGM (1, n) is established with multi-variables. The optimization model is suitable for both equidistance model and non-equidistance model, with high precision and convenience. Examples show the practicality and reliability of the model. © 2015 ejge.