The invention relates to a nonlinear phase position polarized loop circuit mode locking device and a laser device thereof. The nonlinear phase position polarized loop circuit mode locking device comprises a packaging housing, a first collimator, a second collimator, a first reflection corner mirror and a second reflection corner mirror, a beam combiner located between the first reflection corner mirror and the second reflection corner mirror, and a phase position polarization unit located between the beam combiner and the second reflection corner mirror, wherein the first collimator and the second collimator are respectively fixed to two ends of the packaging housing, the first reflection corner mirror and the second reflection corner mirror are located inside the packaging housing, and the beam combiner comprises a semi-transparent semi-reflection plane. The functions of phase position polarization, nonlinear loop circuit mode locking and coupling output are integrated to one three-port optical fiber device through the phase position polarization unit, the beam combiner including the semi-transparent semi-reflection plane and the reflection corner mirrors of the nonlinear phase position polarized loop circuit mode locking device, integration of the phase position polarization and mode locking functions is achieved, much space is saved, and the nonlinear phase position polarized loop circuit mode locking device is simple in structure, low in cost, easy to integrate and good in mode locking state repeatability and is not affected by the environment and a polarization state.