Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase controlled rolling on plate mill was presented and its feature is as follows: (1) Determination of holding thickness can be automatically obtained based on the influence of mill safety limits, tracking zone length and holding time on holding thickness; (2) Determination of holding temperature can be automatically obtained and the holding time can be reduced as much as possible; (3) Algorithm can modify the holding temperature and thickness depending on slab size and product size.