The high viscosity modified asphalt binder is one of the critical factors to determine the performance of the porous asphalt pavement. The wheel tracking test, semi-circular bending test, immersion Marshall test, freeze-thaw splitting test, and immersion Cantabro test were conducted to evaluate the effects of modifier types, dosage and production process on the high-temperature stability, low-temperature cracking resistance, and moisture stability of the high viscosity modified asphalt mixtures. The working mechanism of modifier in the asphalt binder is analyzed by the characteristics of micro morphology. The study results show that different factors have little effects on the air void of the asphalt mixture. Under the same dosage and production process, the asphalt mixture modified by the Thermoplastics Resin(TPR) shows the better low-temperature cracking resistance, similar moisture resistance, and slightly worse high-temperature rutting resistance compared to the one modified by the conventional Tafpack Super (TPS). However, there is no statistically significant difference in pavement performance between them. The increase in the TPR modifier dosage improves all pavement performance of mixtures significantly. When the TPR modifier dosage reaches 13% and 9% corresponding to 70# ^{asphalt binder} and SBS modified asphalt binder used as the base binder, the pavement performance can satisfy the requirements of porous asphalt mixtures. Generally, both modifier dosage and production process have significant effects on all pavement performance. The effect of the former is greater than the latter. From the perspective of micro morphology, it is confirmed that there is particle agglomeration in the asphalt binder for the direct casting method. The incomplete mixing of some modifier particles and binder causes the lower modification efficiency of the direct casting method than that of the shear method. Therefore, the modifier dosage should be appropriately increased when the direct casting method is used. The study findings can provide a beneficial reference for the material design of the porous asphalt pavement.