Abstract: The analysis on the total electric field under the HVAC-HVDC ajacent-tower hybrid transmission lines plays an important role in evaluating the electromagnetic environment nearby. However, few existing research considers the mutual effect of HVAC-HVDC hybrid transmission lines. This paper which considers the mutual effect calculates the total electric field. By comparing the results generated by the calculation with those in published literature, we consider the program reliable. This paper analyzes the influence of sub-conductor radius, sub-conductor splitting number, weather condition and space arrangement of lines. The results show that the total electric field can be effectively reduced by increasing the radius, increasing the splitting number, using the space arrangement with the positive polar closing to AC line. A significant increase in the total electric field on rainy condition should be given special attention.