The invention relates to a coke oven flue gas desulfurization reform process without coke oven shutdown. The coke oven flue gas desulfurization reform process without coke oven shutdown comprises the following steps that firstly, regions on the two sides of a concrete flue are excavated, and trepanning construction is carried out on an external joint of a first flue; secondly, concrete cutting is carried out; thirdly, after cutting is completed, whether cut and formed concrete blocks disengage from the flue or not is checked; whether the air drafting phenomenon at a gap is serious or not is observed, if yes, putty is used for temporary sealing, and then a sling is installed; fourthly, machined flue connection pieces fall onto the concrete flue along a cutting line; fifthly, the concrete blocks which are cut and formed originally are slung; sixthly, a transverse blind plate slides into the concrete flue; seventhly, the flue connection pieces are fixed to the concrete flue; eighthly, expansive cement is used for carrying out dense treatment on leaking positions of joints of the concrete flue and the flue connection pieces, trepanning construction is carried out on an external joint of a second flue, and the second step, the third step, the fourth step, the fifth step, the sixth step, the seventh step and the eighth step are executed again; ninthly, a vertical blind plate is installed in the concrete flue. The process for reforming coke oven flue gas without coke oven shutdown is safe and high in reliability.