The work aims to reduce TiO2 amount in packaging of PET bottles without decreasing the light barrier performance of packaging, to promote recycling process of post consuming packaging. Based on the incompatible characteristics and significant differences in refractive index between poly (4-methyl-1-penene) (PMP) and PET, phase interface and holes were formed during stretching in PET bottle blowing process. At the same time, by adding compatibilizer, the particle size of PMP dispersing in PET was greatly reduced. More two-phase interfaces were formed. On the interface between PMP and PET, the light was refracted and reflected several times to weaken the transmission of light, playing a collaborative effect. The best light barrier result was got when the mass fraction of PMP in masterbatch was 32% and the mass ratio between compatibilizer and PMP was 1∶11. Under the collaborative effect of PMP, the light barrier rate of PET bottle with 3.9% of TiO2 (mass fraction) was equivalent to that of traditional PET bottle with 6% of TiO2 (mass fraction), and the barrier rate of light below 650 nm was greater than 99%. In application of PET bottles, the collaborative application of PMP and compatibilizer can play an effective role of collaborative light barrier and significantly reduce the amount of TiO2.