Bush, who turned 24 a fortnight ago, has plenty of experience in non-league football having had spells at Welling United, Hereford, Gateshead and Woking.
The 6ft-3in centre-half was an important member of the Imps squad last season in the National League Premier making 36 appearances in total, 34 of which were starts, and scored one goal.
The London born defender also has Football League experience from his time with AFC Wimbledon, playing 27 times in their maiden Football League campaign in 2011-12 following their reformation.
All at Chelmsford City would like to welcome Chris to the Club.
(Photo Credit: Lincolnshire Echo)