The invention discloses a space truss formwork 
supporting system and a construction method thereof; the space truss formwork 
supporting system comprises a precast tubular 
pile arranged in the water, a steel hoop fixed on the precast tubular 
pile, a concrete bearing table formed at the top of each 
pile by 
casting and a 
steel tube stand column, a 
diagonal draw bar used for connecting the stand column and a truss chord member node, a space truss composed of the 
steel tube and 
fastener embedded in the bearing table; a jacking is mounted on the stand column of the space truss, the wood brace is arranged on the jacking, a template is mounted on the wood brace for binding the reinforcing 
steel bar and 
casting the concrete beam slab. The space truss formwork 
supporting system takes the precast tubular pile as the fulcrum in the limit situation of the topographic condition, the non-
floor type space truss formwork supporting 
system is used for the construction of the beam and slab reinforcing 
steel bar and concrete, the conventional vertical 
support system is changed into the space horizontal 
support system; the computer analog technology is adopted and the space truss is made of the 
steel tube and used as the bearing 
support system of the cast-in-place beam and slab, the structure safe construction is guaranteed and the construction is quick and safe.