When machining metal parts with laser metal deposition shaping (LMDS) method, if the temperature gradients and energy distributions of different areas inside cladding layer and that between cladding layer and substrate can be effectively controlled with optimal process parameters, then the probability of internal defects of cladding layer can be reduced, and the mechanical properties will be greatly improved. To the problem whether the metal parts made by LMDS contain internal defects, rotatable orthogonal experiments are designed for acquiring the distributions of internal defects of the metal parts under different process parameters. A logistic regression model is built based on these experimental data. Finally an authentication test is taken with the process parameters calculated by the logistic regression model, and no internal defects are found. The results show that the logistic regression model is in good agreement with the actual situation. The logistic regression model proposed in this paper is proved to have the guiding significance for selecting LMDS process parameters.