The invention discloses a stepped large raft construction technology which comprises the following steps: (1) construction preparation; (2) expert argumentation; (3) location setting out; (4) excavation of a foundation pit; (5) manual bottom cleaning; (6) bottom sealing of the foundation pit; (7) arrangements of a lower-step steel bar cage, lower-step inserted barrel steel bars and lower-step embedded parts; (8) installation of lower-step condenser pipes and lower-step temperature measuring lines; (9) lower-step concealed work acceptance; (1) lower-step concrete pouring; (11) lower-step concrete curing and temperature measurement; (12) arrangements of an upper-step steel bar cage, upper-step inserted barrel steel bars and upper-step embedded parts; (13) installation of upper-step condenser pipes and upper-step temperature measuring lines; (14) installation of an upper-step formwork; (15) upper-step concrete pouring; and (16) upper-step concrete curing and temperature measurement. The stepped large raft construction technology is stable, safe and reliable, ensures safe and fast construction, omits secondary erection of formwork supports, reduces the concrete curing cost, the labor cost and other related costs, shortens the construction period, and accelerates the construction progress.