The invention provides a nickel-based high temperature alloy and a preparing method thereof, and specifically a metallurgical nickel alloy with powder not containing the element Nb and objects manufactured from the metallurgical nickel alloy. The nickel-based high temperature alloy comprises, by mass, 12.5-13.5% of Co, 13.75-14.25% of Cr, 2.8-3.2% of Al, 3.8-4.2% of Ti, 3.75-4.25% of W, 3.75-4.25% of Mo, 2.8-3.2% of Ta, 0.17-0.23% of Hf, 0.04-0.06% of C, 0.003-0.015% of B, 0.03-0.07% of Zr and the balance Ni. The high temperature alloy has better structure stability and high-temperature strength, and temperature capability of the alloy is further improved.