A process for preparing high melt strength propylene polymers is provided. The process comprises: blending base propylene polymers with 0.1 to 1% w/w of polyfunctional acrylate monomer, in the presence of 10 to 50 ppm organic peroxide and 0.2 to 20% w/w of an additive such as stabilizer, acid neutralizer, antioxidants or lubricants. The high strength modified propylene polymers obtained have 30 to 60% of increased melt strength than that of the base propylene polymers.