A control method of a power train for a hybrid vehicle is provided. The method includes determining whether an engine corresponds to an optimal operating point when intervention for upshifting is demanded during an HEV driving mode and determining whether an amount of demanded intervention is equal to or less than a value adding maximum intervention torques of a drive motor and an HSG. Each intervention torque of the drive motor and the HSG is determined to adjust a whole energy-collect rate by the drive motor and the HSG to a maximum value of the amount of demanded intervention, and simultaneously, the value adding the intervention torques of the drive motor and the HSG satisfies the amount of demanded intervention.