The invention discloses a factice filling device applied to optical fiber loose tube production. The factice filling device comprises a filling mould base, a fixed shaft and a guide mould sleeve, wherein the filling mould base is connected with the guide mould sleeve through the fixed shaft, an inlet mould is arranged on the left side of the filling mould base, an oil filling pipe is arranged at the bottom of the filling mould base, an oil filling cavity is formed in the filling mould base, a fiber outlet hole mould is arranged on the right side of the filling mould base, a connection thread is arranged on the guide mould sleeve, a fiber passing tube is arranged in the guide mould sleeve, an inner cavity of the inlet mould is communicated with the oil filling cavity, the bottom of the oil filling cavity is communicated with the oil filling pipe, and the central axis of the fiber outlet hole mould coincides with the central axis of the fiber passing tube. The factice filling device disclosed by the invention enlarges contact areas and angles between fiber paste and optical fibers, shortens the fiber passing tube, guarantees optical fiber distribution stability, achieves the purpose that fiber paste is evenly and stably adhered to the surfaces of the optical fibers in high-speed production, achieves stable extrusion of loose tubes at high speed, improves the percent of pass of production and improves production benefits.