<p>A series of MoVTeNbOx catalysts with different Sr doping amounts were prepared by spray-drying method and used in the one-step oxidation of propane to acrylic acid. The results showed that Sr doping does not cause significant damage to the M1 phase structure, and moderate Sr doping increases the relative content of the M1 phase by inhibiting the transformation to the MoO₂ phase. Concurrently, the introduction of Sr alters the pore size distribution of the catalyst, leading to a trend toward a transition from mesoporous to microporous catalysts. The introduction of Sr reduces the surface acidity of MoVTeNbOx, inhibits the peroxidation of acrylic acid, and improves the distribution of surface elements. Moderate Sr doping promotes an increase in the Te⁴⁺ content on the surface of MoVTeNbOx, which is beneficial for the formation of acrylic acid. Compared with the undoped MoVTeNbOx sample, the sample with the Sr/Mo atomic ratio of 0.015 possessed the highest M1 phase content (97%) and the best catalytic performance, with an increase from 46 to 77% for the selectivity to acrylic acid and an increase from 30 to 49% in for the acrylic acid yield.</p> Graphical Abstract <p></p>