The invention discloses a high-temperature-resistant recyclable micro-foam drilling fluid or well-completion fluid, which is composed of: (A) base slurry: 1-2 bentonite, 3-5 salt-resistant clay, 0.2-0.3 soda ash, and 100 parts by weight ;(B) Additives: ①High temperature inhibitor 3-5, ②High temperature viscosifier 2-5, ③High temperature fluid loss reducer 3-6, ④High temperature salt resistance, viscosity raising fluid loss reducer 1-3, ⑤Flow type Regulator 1-3, ⑥ high temperature foaming agent 2-5, ⑦ high temperature foam stabilizer 1-2.5. The invention has high temperature resistance, good carrying and suspension ability in low pressure deep wells, can be used for deep well exploration and development, has strong adaptability, can be used as drilling fluid and well completion fluid, and can be used in high temperature deep wells and low pressure Carbonate formations can also be used in high-temperature, low-pressure, low-permeability mudstone formations, mudstone shale reservoirs and salt-bearing formations. They have the ability to inhibit hydration expansion of mudstone and have a good effect of protecting oil and gas layers. They are mainly used in low-pressure, low-permeability Formation drilling and well completion construction process.