The invention discloses a flame-retardant textile and a flame-retardant adhesive for the flame-retardant textile and a preparation method of the flame-retardant adhesive. The flame-retardant adhesive is prepared from a waterborne white modified emulsion, a water-soluble polymer thickener, a foaming agent, a foam stabilizer, zinc borate, a halogen-free phosphorous nitrogen ammonia-based flame-retardant powder and softened water; the method comprises the steps of weighing a certain amount of softened water and waterborne white modified emulsion in a stirring tank; fully stirring, sequentially adding the foaming agent and the foam stabilizer; weighing the zinc borate, slowly and uniformly adding the halogen-free phosphorous nitrogen ammonia-based flame-retardant powder to a mixture, and stirring while adding; and adding the water-soluble polymer thickener, fully stirring, filtering and discharging to obtain the flame-retardant adhesive. By adopting the halogen-free phosphorous nitrogen ammonia-based flame-retardant powder, the flame-retardant adhesive does not contain halogen and does not cause secondary pollution to the air environment during combustion; since no formaldehyde is added, a product is more environment-friendly; the zinc borate plays a flame-retardant synergistic role as an auxiliary flame retardant; and the flame-retardant adhesive has the advantages of being simple in preparation technology, good in use effect and low in cost.