The nature of hybridization of ‘S’ in ${\mathrm{SO}}_2$ is

The nature of hybridization of ‘S’ in ${\mathrm{SO}}_2 \mathrm{is} {\mathrm{Sp}}^2$

Sum of attached atoms + lone pairs $=2+1=3\Rightarrow {\mathrm{sp}}^2$ hybridization.