The main purpose of this work present a novel method for preparation of the polypropylene/polybutadiene/polyacrylamide (PP/PB/PAM) blends induced by pre-irradiation, the grafting reaction was conducted and completed before melting of the PP, and the formed grafted polymers served as the compatibilizer to enhance uniform dispersion in the melting stage subsequently. The EPR analysis manifests that there was peroxide on the PP powders after irradiation, which decomposed and induced grafting reaction when elevating temperature over 80 °C. The DSC and POM also demonstrated that the crystallization enhancement resulted from the heterogeneous nucleation attributed to both the grafted chains and their interactions. The hydrogen bonding interactions also assisted to construct the heterogeneous network structure in the melts appearing the nonlinear rheological behavior, and exhibited improved melt properties such as strain hardening and shear thinning like that of LCBPP's. Moreover, FTIR analysis confirms that H-bond interactions existed in the melts, their intensity and strength depend on both the PAM content and temperature. Having enhanced the melt strength and elasticity for the network structure in the melt, the PP/PB/PAM blends present well foaming performance especially in the sc-CO2 with water process. The foams are obviously improved in the morphology and uniformity, and with much thinner cell walls, which originates from strengthening cell nucleation and plasticization after incorporation of the PAM. It is possible to tailor the linear polypropylene in a simple and practical way, which might broaden the field of possible applications and make light-weight PP a more competitive comparing to conventional used LCBPPs.