string pattern = @"{LINKTECH\|(\S[^{}]+)}";
string Test = "{BAIDU|xxxxx|yyyy}{LINKTECH|A2004|00000|123123}{GOOGLE|ddddd|ddd}";
Match mc = Regex.Match(Test, pattern, RegexOptions.IgnoreCase);
foreach (Group G in mc.Groups)
Response.Write(G.Value.ToString() + " ");