In order to study the crack resistance performance of the new GRC-PC composite wallboard, a prefabricated integrated product composed of precast concrete (PC) and glass fiber reinforced cement (GRC), taking pure GRC wallboard, pure concrete wallboard and GRC composite wallboard with different thickness as the object, a research has thus been carried out on the crack resistance performance of GRC material and the connection mode between GRC and PC layers, followed by a systematic analysis of the influence of the mass fraction of fiber and rubber powder on the crack resistance of GRC material based on long-term shrinkage tests. Meanwhile, a shrinkage test of GRC-PC composite wallboard is carried out with GRC thickness and composite interface connection mode as variables. The results show that the shrinkage performance of the composite wallboard with a GRC thickness of 15 mm is much better than that of the composite wallboard with a GRC thickness of 10 mm; of the three methods of butt joint, roughening and laying steel wire mesh used for the composite interface, the adoption of butt joint for GRC and PC interface can effectively improve the shrinkage function of the composite wallboard as well as its crack resistance.