The invention discloses a multi-purpose bidirectional passive mode-locked all-fiber laser system, aiming to solve the technical problem that it is difficult to simultaneously output two types of ultrashort optical pulses in existing fiber lasers. The system includes a pump source (1), a wavelength division multiplexer (2), an erbium-doped gain fiber (3), a 2×2 output coupler (4), a first 3dB optical coupler (5), a second 3dB optical coupler (6), first polarization-dependent isolator (7), first polarization controller (8), second polarization-dependent isolator (9), second polarization controller (10), dispersion compensation fiber ( 11) and single-mode fiber (14). The 2×2 output coupler (4) outputs bidirectional mode-locked pulses, and its first output end (12) is connected with a single-mode optical fiber (14) outside the cavity for time-domain compression outside the cavity of the output pulses, so as to To obtain ultrashort pulses with high peak power, the second output terminal (13) directly outputs high energy dissipation soliton resonance pulses. The invention has the advantages of low cost and wide application range, and can be used as a high-peak-power femtosecond pulse light source, a high-energy picosecond and nanosecond pulse light source, and can also be used as a seed source for a high-energy pulse amplifier.