Modified concrete foaming agent

The invention discloses a modified concrete foaming agent. The modified concrete foaming agent is prepared from the following components: sodium dodecyl sulfate, triethanolamine, methyl cellulose, sodium alpha-olefinsulfonate, polyallylamine, propane diacid and water. The foaming agent provided by the invention has strong foaming capability and large foam yield per unit volume and allows produced foam to be maintained for a long time; methyl cellulose and triethanolamine are doped, methyl cellulose can guarantee the foaming rate of the foaming agent, triethanolamine can greatly improve foam stability, and mixed modification of the foaming agent by methyl cellulose and triethanolamine enables the foaming agent to have ideal effect and stability of foaming of the mother liquor of the foaming agent to be improved; and the modified concrete foaming agent uses widely available raw materials, has low cost, is simple to prepare, produces fine foam which has good compatibility with a used medium and overcomes the problems of poor foamability and foam stabilization performance, high cost, complex preparation technology and the like in the prior art.