The Drupal Webform does not have the reset button by default. If you want to have one, you can create custom module to alter the form.

function <module>_form_alter(&$form, $form_state, $form_id) {
  if (strpos($form_id, 'webform_client_form_') === 0 || ($form_id=='user_register_form')) {
    $form['actions']['reset'] = array(
      '#type' => 'button',
      '#value' => t('Reset'),
      '#weight' => 100,
      '#validate' => array(),
      '#attributes' => array('onclick' => 'this.form.reset(); return false;'),
    );
  }
}

The above code will add the reset button to all Webform as well as the user registration form.

Done =)

Reference: Drupal Webform – ‘reset’ button