Finite　element　equations　of　electric-mechanical　coupled　piezoelectric　truss　structures　are　deduced　using　linear　piezoelectricity　and　Hamilton＇s　principle.　An　optimal　control　model　of　piezoelectric　smart　trusses　is　established.　It　makes　the　F　maximum　value　of　the　controlled　nodal　displacements　to　be　minimized　and　subjected　to　the　strength　requirements　of　the　structure　and　the　characteristic　of　the　actuators.　Control　variables　of　the　model　are　the　voltages　of　actuators.　The　model　is　transformed　to　a　sequential　linear　programming　ultimately.　For　static　indeterminate　trusses　in　some　case,　the　maximum　stress　in　the　structure　can　be　decreased　to　allowable　limit　by　adjusting　the　length　of　the　member　if　it　exceeds　the　allowable　limit.　When　the　number　of　actuators　is　limited,　if　they　are　distributed　reasonable　L　and　have　sufficient　active　elongation,　effective　control　can　be　realized　also.　The　L　efficiency　of　the　control　model　is　simulated　by　numerical　method.