The invention discloses a stacking type heat exchanger. The stacking type heat exchanger comprises a plurality of stacked fins. The two opposite sides of each fin are bent upwards and form a ventilated air course by being matched with the corresponding upper fin. The adjacent fins are alternately arranged longitudinally and transversely, so transverse air courses and longitudinal air courses which are mutually independent and are spaced in the vertical direction are formed. The heat exchanger is formed by stacking and lapping the fins which are alternately arranged longitudinally and transversely and is made of plastic materials, so formation is easy, and the thickness is controllable. Moreover, the heat exchanger can be made very thin, so the number of the fins can be increased in limited space, the cooling area can be increased, and heat exchange efficiency can be improved. By the adoption of positioning connection through plug pins, slots and bent flangings, the fins can be directly and alternately stacked longitudinally and transversely, and other connecting components are not needed. Besides, the heat exchanger is simple and accurate in positioning.