The present disclosure provides example power amplifier combiner apparatuses and power amplifier circuits. One example power amplifier combiner apparatus includes a signal processing unit and n power amplifier units. The signal processing unit is separately coupled to input terminals of the n power amplifier units. Output terminals of the n power amplifier units are separately coupled to a load. When an output power of the power amplifier combiner apparatus is less than a first threshold, the signal processing unit controls a first power amplifier unit to operate. When the output power is greater than or equal to an ith threshold and is less than an (i+1)th threshold, the signal processing unit controls the first i+1 power amplifier units to operate. When the output power is not less than an (n−1)th threshold, the signal processing unit controls the n power amplifier units to operate, where i=1, . . . , or n−2.