To provide the polymerization method of a propylene-based block copolymer, with which short-pass particles are selectively inactivated, and catalytic activity and gel suppression are balanced.

The continuous production method of a propylene-based block copolymer is disclosed, which includes using n (n4) of connected polymerization tanks, producing the homopolymer component of propylene in the first to (n-1)-th polymerization tanks in the presence of (A) a solid catalyst component and (B) a Ziegler-Natta catalyst formed of an organic aluminum compound, and producing a copolymer component comprising propylene and ethylene in the n-th polymerization tank, wherein polymerization in the second to (n-1)-th polymerization tanks and polymerization in the n-th tank are carried out in the presence of an alcohol.