Abstract: A preparation method for a flame-retardant and corrosion-resistant fiber bamboo substrate comprises the following steps of: 1) cutting raw bamboo into bamboo filaments; 2) flame-retardant treatment: soaking the bamboo filaments prepared in Step 1) in aqueous solution of a flame retardant; 3) drying: drying the flame-retardant treated bamboo filaments at 55° C. to 65° C.; 4) carbonized pyrolysis: feeding the dried bamboo filaments into a carbonized pyrolysis kiln; and 5) sequentially gumming, post-gumming drying, pressing, curing, maintaining and splitting to obtain a bamboo substrate.