When excess amount of sulphur dioxide is passed through lime water the product formed is,

When we pass sulphur dioxide through lime water, it results in the formation of calcium sulphite.
When we pass sulphur dioxide through lime water, it results in the formation of white precipitates of calcium sulphite which reacts with excess sulphur dioxide in order to form calcium hydrogen sulphite.

The said reaction can be represented as:
$\mathit{Ca}{\left(\mathit{OH}\right)}_2+S{O}_2\to \mathit{CaS}{O}_3+H_{2}O$

${\mathit{CaSO}}_3+{\mathit{SO}}_2{+H}_{2}O \to \mathit{Ca}(\mathit{HS}{O}_3{)}_2$

Hence, when sulphur dioxide is passed through lime water the product formed is Calcium hydrogen sulphite.