Qianwan subsea tunnel in Shenzhen consists of two sections, i.e., the shieldbored tunnel section and the mined tunnel section, for which prefabricated reinforced concrete segment lining consisting of 6 segments per ring is adopted. Due to the complex geological conditions, high gradient requirements and the rowed piles under which the shield machine bores through, it is of great difficulties to conduct the segment erections. For the two special portions of the tunnel, i.e., the tunnel portion where the shield machine bores underneath through the rowed piles and the tunnel portion where the shield machine advances through the mined tunnel section, three segment erection patterns, i.e., normal erection pattern, directionmodification erection mode and pattern of erection for curved sections, are adopted, which results in high segment erection quality. The article places it emphasis on the presentation of the aforedescribed segment erection technology adopted for the two special tunnel portions.