Using a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{ -1}$ recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, an amplitude analysis of the decay $D_{ s}^{ +} \to \pi^{ +}\pi^{ 0}\pi^{ 0}$ is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $D_{ s}^{ +} \to \pi^{ +}\pi^{ 0}\pi^{ 0}$ is measured to be $(0.50\pm 0.04_{ \text{ stat}}\pm 0.02_{ \text{ syst}})\%$. The absolute branching fraction of the intermediate process $D_{ s}^{ +} \to f_0(980)\pi^{ +}, f_0(980)\to\pi^{ 0}\pi^{ 0}$ is determined to be $(0.21\pm 0.03_{ \text{ stat}}\pm 0.03_{ \text{ syst}})\%$.
Categories: hep-ex