In order to accurately predict the incident critical heat flux(ICHF,the heat flux at the heated surface when CHF occurs) of a water-cooled W/Cu monoblock for a divertor,the exact knowledge of its peaking factors(f_p) under one-sided heating conditions with different design parameters is a key issue.In this paper,the heat conduction in the solid domain of a water-cooled W/Cu monoblock is calculated numerically by assuming the local heat transfer coefficients(HTC)of the cooling wall to be functions of the local wall temperature,so as to obtain f_p.The reliability of the calculation method is validated by an experimental example result,with the maximum error of 2.1% only.The effects of geometric and flow parameters on the f_p of a water-cooled W/Cu monoblock are investigated.Within the scope of this study,it is shown that the f_p increases with increasing dimensionless W/Cu monoblock width and armour thickness(the shortest distance between the heated surface and Cu layer),and the maximum increases are 43.8% and 22.4% respectively.The dimensionless W/Cu monoblock height and Cu thickness have little effect on f_p.The increase of Reynolds number and Jakob number causes the increase of f_p,and the maximum increases are 6.8% and 9.6% respectively.Based on the calculated results,an empirical correlation on peaking factor is obtained via regression.These results provide a valuable reference for the thermal-hydraulic design of water-cooled divertors. In order to precisely predict the incident critical heat flux (ICHF, the heat flux at the heated surface when CHF occurs) of a water-cooled W / Cu monoblock for a divertor, the exact knowledge of its peaking factors (f_p) under one- sided heating conditions with different design parameters is a key issue. In this paper, the heat conduction in the solid domain of a water-cooled W / Cu monoblock is calculated numerically by assuming the local heat transfer coefficients (HTC) of the cooling wall to be functions of the local wall temperature, so as to obtain f_p. reliability of the calculation method is validated by an experimental example result, with the maximum error of 2.1% only. these effects of geometric and flow parameters on the f_p of a water -cooled W / Cu monoblock are investigated. Due in the scope of this study, it is shown that the f_p increases with increasing dimensionless W / Cu monoblock width and armor thickness (the shortest distance between the heated surface and Cu layer), and the maximumincrease were 43.8% and 22.4% respectively. The dimensionless W / Cu monoblock height and Cu thickness have little effect on f_p. increase of Reynolds number and Jakob number causes the increase of f_p, and the maximum increase are 6.8% and 9.6% respectively . Based on the calculated results, an empirical correlation on peaking factor is derived via regression. These results provide a valuable reference for the thermal-hydraulic design of water-cooled divertors.