Abstract: This study utilized conventional observation data, S-band dual polarization radar data, wind profile radar data, and ERA5 (0.25°×0.25°) reanalysis data, etc., to examine the extreme wind and continuous squall lines that affected Zhejiang on April 2, 2024. The environmental conditions, structure and development mechanism, and causes of extremely strong winds of the two continuous squall lines, which affected Zhejiang under a given weather background, were compared and analyzed. The results revealed the following: (1) Similar to the southwest jet type squall line, the events of April 2 occurred under the background of strong circulation development in the high-altitude southern trough, middle- and low-level vortex shear, and surface low-pressure trough. After being triggered in different regions, the convection organized into continuous squall lines. The strong southwest jet stream at high and low levels, ground convergence lines, and strong vertical wind shear were favorable conditions for generating and developing squall lines. The two squall lines were independent of each other, with different triggering areas, directions of motion, organization and degree of the convective system, life histories, and wind ranges. (2) The main development mechanism of squall line 1 was a strong dry intrusion in the upper atmosphere, coupled with upward transport of high-energy, high-humidity air in the lower atmosphere, which enhanced convective instability. Simultaneously, strong vertical wind shear in the high and low air, strong ground convergence, and large convective effective potential energy provided lifting and unstable energy conditions for the squall line. The thunderstorm high and cold pool were relatively weak, and the self-development mechanism of the squall line was weak. The main development mechanism of squall line 2 was the strong thunderstorm high and cold pool. The self-development mechanism of the squall line was strong, and the low-level vertical wind shear was almost perpendicular to the direction of the squall line. The low-level vertical airflow continued to rise, and the squall line developed. Meanwhile, the balance between the cold pool and low-level vertical wind shear was maintained, providing conditions conducive to maintaining the life of the squall line. (3) The extreme wind of squall line 1 occurred during the later strengthening process in the northeast section. Cold pool propagation occurred earlier than extreme wind generation. The drag effect of precipitation particles and the downward transfer of momentum contributed to the generation of extreme winds. The extreme wind of squall line 2 occurred during the mature stage, and cold pool propagation occurred later than extreme wind generation. The extreme wind was mainly caused by strong downdrafts.