To generate a scalable and economical approach for preparing tough poly(L-lactide) (PLLA) materials, a series of branched multiblock poly(epsilon-caprolactone)/poly(L-lactide) (BLCL) was synthesized using 3-isocyanatopropyltriethoxysilane (IPTS) as a coupling agent. Triblock poly(L-lactide)-b-poly(epsilon-caprolactone)-b-poly(L-lactide)s (HO-LCL-OH) were synthesized by ring-opening polymerization of L-lactide using polycaprolactone diol as macroinitiator. The branched copolymers, BLCL, were then synthesized with IPTS as a chain extender. The effects of IPTS/HO-LCL-OH ratio on the thermoplasticity and tensile properties were investigated. The copolymers obtained were fabricated into films by hot press molding. The branched multiblock copolymers exhibited good thermoplasticity and remarkable toughness. Using this facile synthetic technique, various diol soft segments might be introduced into PLLA chain to prepare ductile PLLA material.