The present application relates to the technical field of 3D printing, and particularly relates to a printing device and forming method of a
circuit protection layer of a
display device. The printing device of the present application comprises: a main support; the main support has a front end and a rear end along a horizontal direction; at least two barrier wall printing units, which are adapted to print and form barrier walls on the surface of the connection area and / or non-connection area of a flexible circuit board respectively; the printing unit comprises a printing needle; the printing units are arranged at intervals in the direction from the front end to the rear end; a filling glue printing unit is arranged at intervals with the barrier wall printing units in the direction from the front end to the rear end, is located between the rear end and the barrier wall printing units, and is adapted to print filling glue in the space between the multiple barrier walls formed by the multiple printing units to form a
circuit protection layer; the
circuit protection layer covers at least the connection area. The present application can effectively solve the problems of poor uniformity of the film
layer thickness of the circuit
protection layer, influence on packaging, and even possible influence on the display effect.