GB/T 5169.5-2020 specifies the needle-flame test method for electrical and electronic products, solid insulating materials, and combustible materials, simulating the effects of small flames produced under fault conditions to assess fire hazard. The standard defines test apparatus, procedures, result evaluation, and validation requirements. The core setup includes a burner of specific specifications, a gas flow control valve, instruments for measuring flame height and temperature, and a test chamber without ventilation with a volume of no less than 0.5 m³. Propane or butane with a purity of no less than 95% is used as fuel. After adjusting the flame height to 12 mm ± 1 mm, the flame is applied to the specimen. The combustion behavior and flame spread are observed to provide a basis for evaluating the fire safety of products.