The present disclosure provides a pose determining method for a mobile robot as well as an apparatus and a mobile robot thereof. The method includes: obtaining a first position of a mobile robot in each local map after building an initial local map corresponding to a current environment and rotating; determining first environmental contour points of each of the local maps and corresponding first gradient directions, and obtaining a relative position of each of the first environmental contour points and the corresponding first position; building an angle histogram in each of the local maps; determining a second position of second environmental contour points of a global map and corresponding second gradient directions; and predicting a third position in the global map of the mobile robot, counting an appearance amount of the third positions, and determining a target pose of the mobile robot in the global map.