A molding machine system that is capable of freely setting of execution timings for individual operations, such as metal mold heating, molding material injection, pressure retention and cooling, in each molding cycle. There is provided a molding machine system adapted to repeat a sequence of molding cycle, comprising three temperature sensors (101) disposed at different sites of metal mold (100); switching valve unit (50) equipped with medium channels for realization of switched supply of a heating medium from heating unit (1), a cooling medium from cooling unit (30) and a pressure air to the metal mold (100) and recovery thereof; and control means (64) equipped with a program for temperature judgment and a timer and fitted to the switching valve unit (50), wherein any temperature detected by the three temperature sensors (101) is judged by the program for temperature judgment, and wherein on the basis of results of the judgment combined with time setting signal by the timer, there are carried out molding behavior controls including arbitrary supply control for the heating medium, cooling medium and pressure air fed to the metal mold (100) and arbitrary supply control of molding material to the metal mold (100).