Abstract: Passive ultra-low-energy buildings take indoor environment and energy consumption indicators as binding targets, reducing the energy demand of the building itself. The goal is to create a healthy and comfortable indoor environment with extremely low energy consumption, achieving a balance between comfort and energy efficiency, which has won high recognition and policy support from governments at all levels and industry authorities. Combining the specific implementation of a passive ultra-low-energy residential project in a cold region, it explores the practical application of the design standards for passive ultra-low-energy residential buildings in aspects such as the envelope structure system, exterior wall and window system, treatment of key thermal bridges, and enhancement of airtightness.