A planar lightwave circuit structure based on a printed circuit board and its manufacturing method are provided. The manufacturing method includes: S1, preparing the printed circuit board; S2, adhering the lower cladding layer to one side of the printed circuit board, and then annealing process carried out; S3, jetting a lightwave circuit material on an upper surface of the lower cladding layer in a predetermined route through an electrohydrodynamic jet printing device to form lightwave circuit lines to be cured, the lightwave circuit material being a slurry containing silver ions and an ultraviolet (UV) curing agent; S4, curing the lightwave circuit lines through irradiation of UV light, the UV light irradiating onto the lightwave circuit lines through a lens assembly with slits; and S5, depositing an upper cladding layer on the lower cladding layer and the lightwave circuit lines, and then solidifying treatment carried out.