In order to improve the thermal-hydraulic performance of Printed Circuit Heat Exchanger (PCHE), the structural optimization and design of Z-type PCHE is carried out based on the multi-objective optimization method. The results show that the channel with regular hexagonal cross-section possesses the better thermal-hydraulic performance, the effect of the pinch angle is small enough that it can be negligible considered. The structure has the better performance when the regular hexagonal cross-section channel side length is 0.6 mm, bending angle is 20 degrees, and the pitch length is 15 mm. Based on the structural optimization, a novel Z-type PCHE with asymptotic channel is proposed, and then its strength assessment, exergy destruction and economic analysis are conducted. It is determined that the structural performance is the best when the side length of the regular hexagonal channel section is 0.6 mm and the circular diameter is 1.1 mm. Compared to that the traditional semicircular channel section, the thermal-hydraulic performance of the novel Z-type PCHE is increased by 15.74 % and 18.58 %, respectively. Energy damage loss is reduced by 5.21 %, and total cost is reduced by 3.53 %. The present work bridges the gap for optimization design of the Z-type PCHE, and it is of great significance for improving the thermal-hydraulic performance and operation reliability of the Z-type PCHE.