Disclosed is a stream mixing distribution system, and the stream mixing distribution system is composed of a refrigerant pipe (3), a quench box (4), a rectification sieve tray (5) and a distributor disc (6), wherein, the refrigerant pipe (3) is positioned at the upper part of the quench box (4) or positioned in an annular space surrounded by the outer wall of the quench box (4) and the inner wall of a reactor (2), the rectification sieve tray (5) is positioned at the lower part of the quench box (4), the distributor disc (6) is positioned at the lower part of the rectification sieve tray (5), and a plurality of distributors (26) are evenly distributed on the distributor disc (6), and the system is characterized in that each distributor (26) is composed of a bubble cap (27), a center pipe (29), a journal (31) and a rotational flow structure (30), the center pipe (29) is a circular pipe with two open ends, and the bottom part thereof is fixed on the distributor disc, the bubble cap (27) of each distributor is fixed above the center pipe (29) through the journal (31), and the rotational flow structure (30) is fixed at the top part of the center pipe (29) or the outlet of the center pipe (29). The stream mixing distribution system has better mixing distribution effects, and can also save the inner space of the reactor.