Disclosed is a kind of polyurethane basic foaming agent comprising tertiary amine salt and propanolamine salt, the pH value of this basic foaming agent is between 8.5-9.5, and this foaming agent comprises: 1) contains the following general The first compound mixture (M1) of the organic tertiary amine salt compound class of formula (I): A ‑ [B + ] p (I), where B + Is the cation of +1-valent organic tertiary amine B, A ‑ Yes: CO 3 2‑ , HCO 3 ‑ , or CO 3 2‑ with HCO 3 ‑ 2) a second compound comprising N-monohydroxypropyl-ammonium carbonate compound of general formula (II) and N,N'-di(hydroxypropyl)-ammonium carbonate compound of general formula (II) A compound mixture (M2): (RN + h 3 )(N + h 4 )CO 3 2‑ (II), or (RN + h 3 ) 2 CO 3 2‑ (III), in the formula, R is hydroxypropyl; the molar ratio of the compound of general formula (II) to the compound of general formula (III) is 1:0 to 1:1.0. Blowing agents are suitable for use in the preparation of polyurethane spray foam materials.