The invention provides a uniform distribution tubular heat exchanger in-pipe flow inlet and outlet tube box structure. The tube bundle heat transferring uniform effectiveness can be effectively improved, and heat transfer disequilibrium caused by tube bundle non-uniform flow is reduced. The uniform distribution tubular heat exchanger in-pipe flow inlet and outlet tube box structure comprises an inlet tube box, tube bundles and an outlet tube box which are sequentially connected, comprises an inlet tee joint and even numbers of symmetrically-arranged inlet tubes which are connected with a heatexchange working medium inlet in sequence, and further comprises an outlet tee joint and even numbers of symmetrically-arranged outlet tubes which are connected with a heat exchange working medium outlet in sequence; the inlet tube box and the outlet tube box are separated through a middle separating plate and are connected with inlets and outlets of the tube bundles through a front end tube plate; an inlet tube extends into the inlet tube box, the side, back to the first tube pass tube bundle, of the inlet tube is provided with a plurality of incline holes punched in a downwards-inclined manner; and the outlet tube extends into the outlet tube box, and the side, facing the second tube pass tube bundle, of the outlet pipe is provided with a plurality of horizontally-punched flat holes.