Searle took over after Hakan Hayrettin left to join John Still at Maidstone United.
He did a great job - and gave fans hope for the future after producing a young side who cast aside their relegation to secure a number of impressive results.
But he won’t be staying to take the club next season, expected to be in the National League South.
Chairman Lee Harding said he was disappointed but accepts the decision.
“I'd like to thank Danny for his four months at the club,” he told the club’s website.
“He gave it his best shot and some of the results and performances will live long in the memory.
“Danny will always be welcome and we wish him the best of luck in his new role."