据我所知这种签证不能在英国境内续签,只能回中国签。曾有朋友尝试过,还是预约的面签,结果被告知除非非常特殊的情况(例如在英国突发大病无法登机等),这种签证不能在英国境内续签,只能回居住国签证。而且1年内访问签证不能在英国居住超过6个月,所以你如果之前的签证已经居住了6个月,有可能马上再签证的话未必会拿得到签证。

。ukba。homeoffice。gov。uk/visas-immigration/while-in-uk/extending-stay/ If you currently have temporary permission to stay in the UK, you may be able to extend this permission and stay here longer。

If you came here as a visitor, you cannot extend your permission to stay as a visitor beyond 6 months in most cases - however, in some circumstances you may be able to switch into a different immigration category。