你可以
selectName.options[i].parentNode.removeChild(selectName.options[i])or selectName.options[i] = null
selectName.options[i].parentNode.removeChild(selectName.options[i])or selectName.options[i] = null
调试欢乐多
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select>
<input type="button" value="go" onclick="test.options[1].style.display='none'" />