In order to investigate the fracture behavior of cement mortar with fly ash（FA） at early age， cement was replaced with FA to fabricate cement mortar notched beams. Specimens at 1， 2， 3 d were subjected to three-point bending tests and compressive strength tests. Digital image correlation（DIC） technology was adopted to monitor the strain and displacement of specimens， while acoustic emission（AE） technology was used to record the occurrence and accumulation of internal damage. The results show that FA leads to an obvious decrease in the fracture behavior， compressive properties， crack propagation and fracture resistance of cement mortar at early age. It is worthwhile to note that both the fracture process zone and the internal damage range are significantly narrowed for FA cement mortar at early age. With the increase of FA content and shortening of curing age， the fracture parameters of the cement mortar decrease， while the cracks propagation accelerates. It is found that a linear relationship exists between fracture parameters and cube compressive strength.