The invention relates to copper surface treatment liquid and a copper surface treatment method for multilayer printed circuit board manufacturing, and belongs to the technical field of printed circuits. According to the copper surface treatment liquid and the copper surface treatment method, copper surface roughening and medium layer performance optimization for improving interlayer bonding forceare carried out in two stages, wherein the treatment liquid used for the copper surface roughening comprises alkali metal peroxide, alkali metal hydroxide, alkali metal silicate, polyhydroxylated polymer, a metal complexing agent, a copper metal corrosion inhibitor and a molybdate additive with mass concentrations being 20-50g/L, 30-60g/L, 30-60g/L, 3.5-10g/L, 30-60g/L, 3-8g/L and 6-30g/L respectively; and the treatment liquid used for the medium layer optimization comprises alkali metal sulfide, alkali metal phosphate and a silane coupling agent with the mass concentrations being 10-30g/L, 40-160g/L and 7.5-30g/L respectively. The copper surface treatment liquid has better compatibility with the prior art, the low roughness modification of the copper surface can reach the IPC standard, and the copper surface treatment liquid and the copper surface treatment method are favorable for a multilayer board manufacturing technology to meet the challenge brought by the high frequency of transmission signals of a printed circuit board.